A Live Recombinant Avirulent Oral Salmonella Vaccine Expressing Pneumococcal Surface Protein A Induces Protective Responses against Streptococcus pneumoniae
AUTOR(ES)
Nayak, Amiya R.
FONTE
American Society for Microbiology
RESUMO
A live oral recombinant Salmonella vaccine strain expressing pneumococcal surface protein A (PspA) was developed. The strain was attenuated with Δcya Δcrp mutations. Stable expression of PspA was achieved by the use of the balanced-lethal vector-host system, which employs an asd deletion in the host chromosome to impose an obligate requirement for diaminopimelic acid. The chromosomal Δasd mutation was complemented by a plasmid vector possessing the asd+ gene. A portion of the pspA gene from Streptococcus pneumoniae Rx1 was cloned onto a multicopy Asd+ vector. After oral immunization, the recombinant Salmonella-PspA vaccine strain colonized the Peyer’s patches, spleens, and livers of BALB/cByJ and CBA/N mice and stimulated humoral and mucosal antibody responses. Oral immunization of outbred New Zealand White rabbits with the recombinant Salmonella strain induced significant anti-PspA immunoglobulin G titers in serum and vaginal secretions. Polyclonal sera from orally immunized mice detected PspA on the S. pneumoniae cell surface as revealed by immunofluorescence. Oral immunization of BALB/cJ mice with the PspA-producing Salmonella strain elicited antibody to PspA and resistance to challenge by the mouse-virulent human clinical isolate S. pneumoniae WU2. Immune sera from orally immunized mice conferred passive protection against otherwise lethal intraperitoneal or intravascular challenge with strain WU2.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=108410Documentos Relacionados
- A live avirulent mutant Legionella pneumophila vaccine induces protective immunity against lethal aerosol challenge.
- Oral immunization with recombinant Salmonella typhimurium expressing surface protein antigen A of Streptococcus sobrinus: dose response and induction of protective humoral responses in rats.
- Oral immunization with recombinant Salmonella typhimurium expressing surface protein antigen A of Streptococcus sobrinus: persistence and induction of humoral responses in rats.
- Immune Responses to Recombinant Pneumococcal PspA Antigen Delivered by Live Attenuated Salmonella enterica Serovar Typhimurium Vaccine
- Intranasal Vaccination with Pneumococcal Surface Protein A and Interleukin-12 Augments Antibody-Mediated Opsonization and Protective Immunity against Streptococcus pneumoniae Infection